Modified porous microspheres, methods for their preparation, separation devices, and applications thereof

Abstract

The present application relates to the field of gas separation, discloses modified porous microspheres and preparation method thereof, separation device and their application, the modified porous microspheres include surface benzene ring sulfonated and halogenated modified styrene-divinylbenzene-acrylonitrile copolymer.The preparation raw material of the modified porous microspheres disclosed in the present application is simple and easy to obtain, and the gas chromatography filling column prepared by using the modified porous microspheres disclosed in the present application can effectively separate trace O2 and Ar in hydrogen for PEMFC, the analysis process can be completed within 3min, qualitative and quantitative analysis of target objects can be simultaneously carried out, the minimum detection limit is as low as 10ppm, and the long-term operation of PEMFC is effectively ensured.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of gas separation, in particular to a modified porous microsphere, a preparation method of the modified porous microsphere, the modified porous microsphere prepared by the method, a separation device, and application of the modified porous microsphere or the separation device in separating O2 and Ar in a hydrogen raw material or in determining the content of O2 and Ar in the hydrogen raw material. BACKGROUND

[0002] Hydrogen energy is a high-efficiency, clean, low-carbon and environmentally friendly secondary energy, and is one of the ideal solutions to replace petroleum fuel in the application of new energy power vehicle industry. Hydrogen fuel cell vehicle (FCV) is a new energy vehicle that uses proton exchange membrane fuel cell (PEMFC) to convert chemical energy into electrical energy through the reaction between hydrogen and oxygen under the action of a catalyst, and realizes zero emission and pollution-free by taking water as the final product. The quality of hydrogen as fuel directly determines the performance and service life of the fuel cell. At present, fossil fuel is one of the important sources of hydrogen, and O2 and Ar impurities are inevitably brought in during the production of hydrogen from fossil fuel. O2 and Ar impurities are one of the main factors affecting the durability of fuel cells. Therefore, unlike refinery hydrogen, FCV hydrogen not only requires high purity, but more importantly, the control of key trace impurities, otherwise it will seriously affect the operating efficiency and service life of the fuel cell.

[0003] The analysis of impurity components in PEMFC hydrogen is basically a trace analysis of less than one part per million (ppm). The trace amounts of O2 and Ar in hydrogen can be detected by thermal conductivity detector (TCD) and pulsed discharge helium ionization detector (PDHID). The sensitivity of TCD and PDHID detectors can meet the requirements of ppm-level trace detection. The boiling point of hydrogen is -252.7℃ at normal pressure, the boiling point of oxygen is -183.1℃ at normal pressure, and the boiling point of argon is -185.7℃ at normal pressure. It is almost impossible to separate O2 and Ar with very close boiling points by using general chromatographic columns. O2 and Ar need to be separated by weak bonding of substances and other chemical properties. If O2 and Ar in hydrogen cannot be completely separated on a chromatographic column, it is difficult to meet the requirements of ppm-level trace detection. The present application develops a preparation process of gas phase packed chromatographic column. The gas phase packed chromatographic column produced by this process can effectively separate O2 and Ar in hydrogen. The completely separated O2 and Ar can meet the requirements of ppm-level trace detection. PEMFC hydrogen production enterprises can use this chromatographic column to detect trace amounts of O2 and Ar in hydrogen, so as to ensure the long-term operation of PEMFC. SUMMARY

[0004] The application aims to provide a modified porous microsphere, a preparation method and application thereof, so as to realize effective separation of O2 and Ar in hydrogen, and to make the completely separated O2 and Ar meet the ppm-level trace detection requirement, and ensure long-term operation of PEMFC.

[0005] In order to achieve the above-mentioned purpose, the application provides a modified porous microsphere, which comprises a styrene-divinylbenzene-acrylonitrile copolymer modified by surface benzene ring sulfonation and halogenation.

[0006] The application provides a preparation method of the modified porous microsphere, which comprises the following steps:

[0007] (1) mixing styrene, divinylbenzene and acrylonitrile with an initiator and a pore-forming agent to obtain a monomer solution;

[0008] (2) mixing the monomer solution with a dispersion phase containing a dispersant and performing suspension polymerization to obtain a porous microsphere of a styrene-divinylbenzene-acrylonitrile copolymer;

[0009] (3) performing sulfonation and halogenation reduction treatment on the porous microsphere of the styrene-divinylbenzene-acrylonitrile copolymer under acidification conditions to obtain the modified porous microsphere.

[0010] The application provides the modified porous microsphere prepared by the method.

[0011] The application provides a separation device filled with the modified porous microsphere.

[0012] The application provides application of the modified porous microsphere or the separation device in separation of O2 and Ar in hydrogen raw material or in determination of the content of O2 and Ar in hydrogen raw material.

[0013] The preparation raw material of the modified porous microsphere is simple and easy to obtain, and the cost is low, the preparation process is simple, there is no environmental pollution, and the prepared modified porous microsphere has high consistency.

[0014] The chromatographic column filled with the modified porous microsphere can effectively separate trace O2 and Ar in hydrogen for PEMFC, the analysis time is short, the whole analysis process can be completed within 3 min, the minimum detection limit is as low as 10 ppm, and the long-term operation of PEMFC is effectively ensured. Moreover, the chromatographic column is suitable for various gas chromatographs, and has a wide application range. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 The structure schematic diagram of the modified porous microsphere is shown.

[0016] Figure 2 A GC-MS chromatogram showing separation of O2and Ar in hydrogen gas in Example 1 is shown.

[0017] Figure 3 A GC-NCD chromatogram showing separation of O2and Ar in hydrogen gas in Example 1 is shown.

[0018] Figure 4 A GC-MS chromatogram showing separation of O2and Ar in hydrogen gas in Comparative Example 1 is shown.

[0019] Figure 5 A GC-MS chromatogram showing separation of O2and Ar in hydrogen gas in Comparative Example 2 is shown.

[0020] Figure 6 A GC-NCD chromatogram showing separation of O2and Ar in hydrogen gas in Comparative Example 3 is shown.

[0021] Figure 7 A chromatogram obtained using a 13X molecular sieve packed column in Comparative Example 3 is shown. DETAILED DESCRIPTION

[0022] The endpoints of the ranges and any values disclosed herein are not limited to the precise values recited as the exact dimensions are not critical to the properties. The endpoints of the ranges and any numerical values are approximations which are understood to encompass a range of values which are near the value itself that are postulated to be the same as that value in light of the stated objectives and a property disclosed. The range of values disclosed herein includes all values between each pair of values.

[0023] A first aspect of the present application provides a modified porous microsphere, the modified porous microsphere comprising a styrene-divinylbenzene-acrylonitrile copolymer modified by surface sulfonation and halogenation of benzene rings. A schematic structure thereof can be shown as Figure 1

[0024] Preferably, in the styrene-divinylbenzene-acrylonitrile copolymer, the weight ratio of styrene units, divinylbenzene units and acrylonitrile units is (25-45, which can be 25, 30, 35, 40, 45 and any range between any two values):(20-40, which can be 20, 25, 30, 35, 40 and any range between any two values):(10-30, which can be 10, 15, 20, 25, 30 and any range between any two values).

[0025] ​Preferably, in the modified porous microspheres, the content of styrene-divinylbenzene-acrylonitrile copolymer is 92-98 wt%, for example, it can be 92, 94, 96, 98 wt% and any range consisting of any two values between them, preferably 94-96 wt%; the content of sulfonic acid group is 1.5-5.5 wt%, for example, it can be 1.5, 2, 3, 4, 5, 5.5 wt% and any range consisting of any two values between them, preferably 2.8-4.2 wt%; the content of halogen group is 0.5-2.5 wt%, for example, it can be 0.5, 1, 1.5, 2, 2.5 wt% and any range consisting of any two values between them, preferably 1.2-1.8 wt%.

[0026] Preferably, the number average molecular weight of the styrene-divinylbenzene-acrylonitrile copolymer is 10000-60000 g / mol, for example, it can be 10000, 20000, 30000, 40000, 50000, 60000 g / mol and any range consisting of any two values between them.

[0027] Preferably, the divinylbenzene unit is p-divinylbenzene unit and / or m-divinylbenzene unit.

[0028] The halogen group can be a common halogen group in the art, such as Cl and / or Br, preferably, the halogen group is chlorine.

[0029] Preferably, the mass ratio of surface elements of the modified porous microspheres is C (65-75, for example, it can be 65, 66, 68, 70, 72, 74, 75 and any range consisting of any two values between them): O (8-15, for example, it can be 8, 10, 12, 13, 14, 15 and any range consisting of any two values between them): S (6-12, for example, it can be 6, 8, 10, 12 and any range consisting of any two values between them): Cl (7-13, for example, it can be 7, 8, 10, 12, 13 and any range consisting of any two values between them). The content of each element is detected by X-ray fluorescence XRF.

[0030] Preferably, the particle size of the modified porous microspheres is 150-1000 μm.

[0031] Preferably, the pore size of the modified porous microspheres is 20-100 nm.

[0032] Preferably, the BET specific surface area of the modified porous microspheres is 30-40 m 2 / g.

[0033] The above parameters can be determined by BET method.

[0034] Preferably, the modified porous microspheres have a column packing density of 0.2-0.5 g / mL. The column packing density can be determined by weighing and filling the column volume.

[0035] The second aspect of the present application provides a method for preparing modified porous microspheres, comprising:

[0036] 1) mixing styrene, divinylbenzene and acrylonitrile with an initiator and a porogen to obtain a monomer solution;

[0037] (2) mixing the monomer solution with a dispersion phase containing a dispersant and performing suspension polymerization to obtain porous microspheres of styrene-divinylbenzene-acrylonitrile copolymer;

[0038] (3) performing sulfonation and halogen reduction treatment on the porous microspheres of styrene-divinylbenzene-acrylonitrile copolymer under acidification conditions to obtain the modified porous microspheres.

[0039] In the present application, styrene, divinylbenzene and acrylonitrile can all be obtained commercially, and their purity can be higher than 90wt%; generally, the monomers also need to be treated to remove inhibitors before polymerization, and the method for removing inhibitors is a conventional method in the art, which will not be described here.

[0040] Preferably, the divinylbenzene is p-divinylbenzene and / or m-divinylbenzene.

[0041] Preferably, in step (1), the initiator is a peroxide and / or an azo compound, preferably at least one selected from azobisisobutyronitrile, azobisisoheptyl nitrile, benzoyl peroxide and tert-butyl hydroperoxide.

[0042] Preferably, the porogen is selected from one or more of ethyl acetate, paraffin, gasoline, kerosene, n-C12-C18 alkyl alcohol (such as dodecanol, tridecanol, hexadecanol, octadecanol, etc.).

[0043] Preferably, the amount of styrene, divinylbenzene, acrylonitrile, initiator and porogen is (25-45, for example, can be 25, 30, 35, 40, 45 and any range consisting of any two values):(20-40, for example, can be 20, 25, 30, 35, 40 and any range consisting of any two values):(10-30, for example, can be 10, 15, 20, 25, 30 and any range consisting of any two values):(0.5-3, for example, can be 0.5, 1, 1.5, 2, 2.5, 3 and any range consisting of any two values):(0.5-3, for example, can be 0.5, 1, 1.5, 2, 2.5, 3 and any range consisting of any two values) by weight.

[0044] Preferably, the solvent of the monomer solution is selected from at least one of toluene, p-xylene and ethylbenzene.

[0045] Preferably, the solvent of the monomer solution is used in an amount of 3-20 parts by weight, for example, 3, 5, 10, 15, 20 parts by weight and any range consisting of any two of the values, compared to 1 part by weight of the total weight of styrene, divinylbenzene and acrylonitrile.

[0046] Preferably, in step (2), the dispersant is preferably one or more of C12-C22 alkyl tri C1-C6 alkyl ammonium halides, preferably one or more of dodecyl trimethyl ammonium chloride, dodecyl trimethyl ammonium bromide, dodecyl triethyl ammonium chloride, dodecyl triethyl ammonium bromide, tetradecyl trimethyl ammonium chloride, tetradecyl trimethyl ammonium bromide, tetradecyl triethyl ammonium chloride, tetradecyl triethyl ammonium bromide, hexadecyl trimethyl ammonium chloride, hexadecyl trimethyl ammonium bromide, hexadecyl triethyl ammonium chloride, hexadecyl triethyl ammonium bromide, octadecyl trimethyl ammonium chloride, octadecyl trimethyl ammonium bromide, octadecyl triethyl ammonium chloride and octadecyl triethyl ammonium bromide, more preferably one or more of dodecyl trimethyl ammonium chloride, dodecyl trimethyl ammonium bromide, dodecyl triethyl ammonium chloride, dodecyl triethyl ammonium bromide, hexadecyl trimethyl ammonium chloride, hexadecyl trimethyl ammonium bromide, hexadecyl triethyl ammonium chloride and hexadecyl triethyl ammonium bromide.

[0047] Preferably, the dispersed phase is an aqueous phase.

[0048] Preferably, the water is used in an amount of 3-20 parts by weight, for example, 3, 5, 10, 15, 20 parts by weight and any range consisting of any two of the values, and the dispersant is used in an amount of 0.01-0.05 parts by weight, for example, 0.01, 0.03, 0.05 parts by weight and any range consisting of any two of the values, compared to 1 part by weight of the total weight of styrene, divinylbenzene and acrylonitrile.

[0049] The obtained modified porous microspheres can be subjected to a sieving treatment to obtain porous microspheres with a target particle size. The obtained porous microspheres can also be subjected to a drying treatment, which is not particularly limited as long as water can be removed, for example, drying at 100-110℃ for 4-6h. The obtained porous microspheres can be subjected to a sulfonation and halogen reduction treatment.

[0050] Preferably, in step (2), the conditions of the suspension polymerization include a temperature of 50-95℃ and a time of 5-10h.

[0051] The suspension polymerization process preferably uses ultrasonic dispersion and stirring.

[0052] The suspension polymerization process preferably uses gradient heating, specifically, the suspension polymerization process preferably uses 0.5-1.5h of reaction at 55-65℃, then 1-2h of reaction at 80-90℃, and then 3-5h of reaction at 85-95℃.

[0053] In one preferred embodiment of the present application, in step (3), the sulfonating and halogen reduction treatment process comprises: contacting the porous microspheres of styrene-divinylbenzene-acrylonitrile copolymer with sulfite and halide in a mixed solution of sulfuric acid and nitric acid, and performing sulfonating and halogen reduction treatment to obtain the acid-treated product. Preferably, the sulfonating and halogen reduction treatment conditions comprise: a temperature of 50-70℃ (such as 50, 55, 60, 65, 70℃, and any range between any two values), a vacuum degree of less than 0.1Mpa (such as 0.01MPa, 0.02MPa, 0.04MPa, 0.06MPa, 0.08MPa, 0.09MPa, 0.095MPa, 0.098MPa, and any range between any two values), and a time of 6-10h (such as 6, 7, 8, 9, 10h, and any range between any two values).

[0054] In one preferred embodiment of the present application, in step (3), the sulfonating and halogen reduction treatment process comprises: contacting the porous microspheres of styrene-divinylbenzene-acrylonitrile copolymer with sulfite and halide in a mixed solution of sulfuric acid and nitric acid, and performing sulfonating and halogen reduction treatment to obtain the acid-treated product. Preferably, the sulfonating and halogen reduction treatment conditions comprise: a temperature of 50-70℃ (such as 50, 55, 60, 65, 70℃, and any range between any two values), a vacuum degree of less than 0.1Mpa (such as 0.01MPa, 0.02MPa, 0.04MPa, 0.06MPa, 0.08MPa, 0.09MPa, 0.095MPa, 0.098MPa, and any range between any two values), and a time of 6-10h (such as 6, 7, 8, 9, 10h, and any range between any two values).

[0055] In another preferred embodiment of the present application, in step (3), the sulfonating and halogen reduction treatment process comprises: acidifying the porous microspheres of styrene-divinylbenzene-acrylonitrile copolymer, then contacting the acid-treated product with sulfite and halide, and performing sulfonating and halogen reduction treatment to obtain the modified porous microspheres.

[0056] Preferably, in step (3), the acidification process comprises: acidifying the porous microspheres in a mixed solution of nitric acid and sulfuric acid to obtain the acid-treated product.

[0057] Preferably, the conditions of the acidification treatment include: temperature of 50-70℃ (such as 50, 55, 60, 65, 70℃ and any range between any two values), vacuum degree less than 0.1Mpa (such as 0.01MPa, 0.02MPa, 0.04MPa, 0.06MPa, 0.08MPa, 0.09MPa, 0.095MPa, 0.098MPa and any range between any two values), time of 2-6h (such as 2, 3, 4, 5, 6h and any range between any two values).

[0058] Preferably, in the mixed solution of sulfuric acid and nitric acid, the concentration of sulfate is 15-40wt%, such as 15, 20, 25, 30, 35, 40wt% and any range between any two values, more preferably 20-30wt%, the concentration of nitrate is 30-65wt%, such as 30, 35, 40, 45, 50, 55, 60, 65wt% and any range between any two values, more preferably 40-50wt%.

[0059] Preferably, the weight ratio of the mixed solution of sulfuric acid and nitric acid to the porous microspheres is 5-15:1, such as 5:1, 7:1, 9:1, 11:1, 13:1, 15:1 and any range between any two values.

[0060] Preferably, the amount of sulfite is 5-40 parts by weight, such as 5, 10, 15, 20, 25, 30, 35, 40 parts by weight and any range between any two values, compared to 100 parts by weight of porous microspheres, the amount of halide is 5-40 parts by weight, such as 5, 10, 15, 20, 25, 30, 35, 40 parts by weight and any range between any two values.

[0061] Preferably, the sulfite is sodium sulfite and / or potassium sulfite.

[0062] Preferably, the halide is sodium chloride and / or potassium chloride.

[0063] During the process of sulfonation and halogen reduction, heat is generated, when the temperature of the material drops to room temperature, the obtained product can be repeatedly washed and centrifuged by acetone, and the finally separated product is dried to obtain sulfonated and halogenated microsphere powder, that is, the modified porous microspheres of the present application. The obtained modified porous microspheres can also be sieved using a certain mesh size (such as 20-100 mesh) to obtain modified porous microspheres with a specific particle size.

[0064] The third aspect of the present application provides modified porous microspheres prepared by the method as described above.

[0065] The parameters of the modified porous microspheres can be found in the first aspect, which will not be repeated here.

[0066] The fourth aspect of the present application provides a separation device, wherein the modified porous microspheres as described above are filled in the separation device.

[0067] Preferably, the separation device is a chromatographic column.

[0068] Preferably, the chromatographic column filling density of the modified porous microspheres is 0.2-0.5 g / mL.

[0069] The preparation method of the chromatographic column can be a conventional method in the art, and those skilled in the art can prepare the chromatographic column according to the needs.

[0070] For example, regarding the selection of the chromatographic column tube, a glass tube, a stainless steel tube or a plastic tube with uniform inner diameter and appropriate length can be selected, such as a filling column with an inner diameter of 1.2-4 mm and a length of 0.5-3 m, and the shape can be U-shaped or spiral-shaped.

[0071] Before use, the column tube can be directly rinsed with clean water for about 20 minutes, then a dilute acid or a dilute base (generally 0.05-0.2 mol / L of nitric acid, hydrochloric acid or sodium hydroxide) is poured into the column tube, and soaked for more than 2 hours, then washed with clean water until the washing liquid is neutral, then the same method is used to inject ethanol or acetone, and soaked for more than 2 hours, then sequentially washed with distilled water and ethanol, and dried in an oven.

[0072] The volume of the microspheres required by the chromatographic column is estimated according to V=Lπr 2 , wherein r is the radius of the column (cm); L is the length of the column (cm); and V is the volume of the column (mL).

[0073] The filling method of the chromatographic column can be: a small funnel is connected to the outlet of the chromatographic column which has been washed and dried, and the prepared microspheres are filled into the column in batches, while constantly tapping the column wall until it is filled to 1.5 cm away from the column port. Move the glass funnel to the inlet of the chromatographic column, plug a small amount of silanized glass wool at the outlet end, and wrap it with a thin layer of cotton or 2 layers of gauze, connect it to the vacuum pump through a rubber tube, start the vacuum pump, continue to slowly add the prepared filler from the funnel, and constantly tap the column wall to make it fill uniformly and tightly. After filling is completed, a small amount of silanized glass wool is also plugged at the inlet end, and is appropriately compressed to keep the filler in the column from moving.

[0074] The obtained chromatographic column can be aged before use. The aging can be performed by connecting the inlet of the chromatographic column to a gasification chamber, not connecting the outlet to a detector, and passing carrier gas (N2) at a flow rate of 15 mL / min, and gradually increasing the temperature to 250℃, and aging at the temperature for at least 24 h.

[0075] The chromatographic column can be connected to a gas chromatograph, and the content of NO and N2O can be determined by using a MSD detector or a NCD detector. The control, recording, qualitative analysis and quantitative analysis of the chromatographic separation system can be completed by a chromatographic work station.

[0076] The fifth aspect of the present application provides the use of the modified porous microspheres or the separation device in separating or determining the content of NO and N2O in a propylene raw material.

[0077] The use conditions of the chromatographic column can include: the carrier gas is helium, the flow rate of the carrier gas is 0.8-15 mL / min, the pressure of the carrier gas is 0.3-0.6 Mpa, the quantitative ring is 0.2-3 mL, the split ratio is 1:1-1:10, and the temperature of the chromatographic column is 40-100℃.

[0078] The present application will be described in detail by way of examples.

[0079] Unless otherwise specified, the reagents and materials used are commercially available.

[0080] In the following examples, the concentration of sulfuric acid in the mixed solution of nitric acid and sulfuric acid is 23.3 wt%, and the concentration of nitric acid is 46.7 wt%.

[0081] Example 1

[0082] This example is used to illustrate the preparation method of the modified porous microspheres and the chromatographic column, and the method for determining the content of the to-be-detected component by gas chromatography.

[0083] 1. Preparation of porous microspheres

[0084] In 100 mL of p-xylene, 7 g of styrene, 6 g of p-divinylbenzene and 4 g of acrylonitrile from which the polymerization inhibitor was removed were mixed with 0.2 g of benzoyl peroxide and 0.2 g of n-octadecanol, and deoxygenated by nitrogen to obtain a monomer phase solution.

[0085] Mix 0.3 g of cetyltrimethylammonium bromide with 100 ml of distilled water, deoxygenate with nitrogen, and obtain an aqueous solution, which is mixed with the monomer phase solution and ultrasonically dispersed for 30 min. The mixed material is transferred to a three-necked flask, deoxygenated with nitrogen for 10 min, and then heated. At a stirring speed of 1040 r / min, the temperature is raised to 60°C and the reaction is carried out for 60 min. The temperature is then raised to 85°C and the reaction is carried out for 90 min. The temperature is then raised to 90°C and the reaction is carried out for 4 h, after which the heating is stopped. After the material temperature cools to room temperature, water vapor distillation is carried out to remove n-octadecanol. After filtration, the filter cake is placed in a fat extractor, extracted with toluene to remove the chain polymer, and the remaining solid is dried and then sieved to obtain solid porous microspheres of 70-80 mesh.

[0086] 2. Modification of the porous microspheres

[0087] Ultrasonically disperse 12 g of the solid porous microspheres prepared in step 1 in 100 mL of a mixed solution of nitric acid and sulfuric acid, and continuously pump and vacuumize with a circulating water pump. Acidify at a temperature of 60°C for 4 h. Then add 3 g of sodium hydrosulfite and 3 g of potassium chloride and continuously stir (and continuously pump and vacuumize with a circulating water pump) to carry out sulfonation and chlorination reduction at 60°C for 2 h. After the mixed solution cools to room temperature, the final separated product is obtained by repeated acetone washing and centrifugal separation, and then dried to obtain sulfonated and chlorinated modified porous microspheres. Sieve the modified porous microspheres of 70-80 mesh for standby use. The pore size of the modified porous microspheres is 20-100 nm, and the specific surface area is 30-40 m 2 / g.

[0088] The mass ratio of the surface elements of the modified porous microspheres is C 70:O 11:S 9:Cl 10 by XRF analysis.

[0089] 3. Preparation of a gas chromatography column

[0090] Select a U-shaped stainless steel chromatography column tube with an inner diameter of 2 mm and a length of 3 m. First, rinse the chromatography column tube with water for 20 min. Then, fill the chromatography column tube with 0.1 mol / L sodium hydroxide and soak for 2 h. Then, rinse with water until the washing liquid is neutral. Then, inject ethanol into the chromatography column tube in the same way and soak for 2 h. Then, rinse with distilled water and ethanol in turn. Finally, dry the chromatography column tube in an oven.

[0091] Place a funnel at one end of the dried U-shaped chromatography column tube. Fill the modified porous microspheres prepared in step 2 into the funnel in portions, while continuously tapping the column wall, until the filling reaches 1.5 cm from the column port. Remove the funnel and plug the port with silanized glass wool wrapped in thin layer cotton. Finally, connect this end of the U-shaped chromatography column tube to a vacuum pump through a rubber tube.

[0092] Put the funnel at the other end of the U-shaped chromatographic column tube, turn on the vacuum pump, and continue to fill the prepared modified porous microspheres into the U-shaped chromatographic column tube through the funnel, and constantly tap the column wall to make it fill uniformly and tightly until it is filled to 1.5 cm away from the column port. Remove the funnel and plug the port with silanized glass wool wrapped with thin layer cotton, and press the glass wool to keep the column filling from moving, wherein the packing density of the modified porous microspheres is 0.3 g / mL.

[0093] Connect the inlet of the chromatographic column to the gasification chamber, and do not connect the detector to the outlet end. Pass in carrier gas N2 at a flow rate of 15 mL / min. Increase the temperature in stages to 250℃, and age at 250℃ for 24 h to obtain a gas chromatographic column.

[0094] 4. Application of the chromatographic column (GC-MS)

[0095] Agilent 8890B (GC) gas chromatograph, thermal conductivity TCD detector, control and recording of the chromatographic separation system is completed by CDS workstation, qualitative and quantitative analysis is completed by customized software.

[0096] Separation chromatographic column: the gas chromatographic column prepared in step 3 is used.

[0097] The working conditions of the chromatograph are: the temperature is constant at 50℃, the flow rate is constant at 10 mL / min, the sample size is 0.25 mL, the split ratio is 1:15, the carrier gas is 0.5 Mpa nitrogen (99.9999%), and the quantitative ring is 0.25 mL.

[0098] Hydrogen from a hydrogen storage tank for PEMFC is introduced into GC-TCD for separation and detection through a gas valve, and the obtained chromatogram is as shown in Figure 2 .

[0099] Example 2

[0100] According to the method described in Example 1, the difference is:

[0101] 3. Preparation of the chromatographic column

[0102] A U-shaped stainless steel chromatographic column tube with an inner diameter of 1.5 mm and a length of 2 m is selected.

[0103] 4. Application of the chromatographic column

[0104] Agilent 7890B (GC) gas chromatograph, pulse discharge helium ionization PDHID detector, control and recording of the chromatographic separation system is completed by CDS workstation. Qualitative and quantitative analysis is completed by customized software.

[0105] Separation chromatographic column: the gas chromatographic column prepared in step 3 is used.

[0106] The working conditions of the chromatograph are as follows: the temperature is 70°C, the flow rate is 15 mL / min, the sample amount is 0.50 mL, the split ratio is 1:20, the carrier gas is 0.5 Mpa helium (99.9999%), and the quantitative ring is 0.50 mL.

[0107] The hydrogen from the hydrogen storage tank for PEMFC is introduced into the GC-PDHID through a gas valve for separation and detection, and the obtained chromatogram is as shown in Figure 3 .

[0108] Example 3

[0109] The difference from Example 1 is that:

[0110] 2. Modification of the porous microspheres

[0111] The 12 g of solid porous microspheres prepared in step 1 are ultrasonically dispersed into 100 mL of a mixed solution of nitric acid and sulfuric acid, and then 3 g of sodium hydrosulfite and 3 g of potassium chloride are added while stirring (and vacuum is continuously pumped out by a circulating water pump). Acidification, sulfonation, and chlorination are simultaneously performed at 60°C for 6 h. After the mixed solution is cooled to room temperature, the product after the final separation is dried after repeated acetone washing and centrifugal separation to obtain sulfonated and chlorinated modified porous microspheres. The modified porous microspheres with a pore size of 70-80 mesh are screened for standby use, and the modified porous microspheres have a pore size of 20-100 nm and a specific surface area of 30-40 m 2 / g.

[0112] The hydrogen from the hydrogen storage tank for PEMFC is introduced into the GC-PDHID through a gas valve for separation and detection, and the obtained chromatogram is as shown in Figure 4 .

[0113] Comparative Example 1

[0114] The difference from Example 1 is that: a 5A molecular sieve is used to fill the chromatographic column (Molesieve 5A), and the obtained chromatogram is as shown in Figure 5 .

[0115] Comparative Example 2

[0116] The difference from Example 1 is that: the porous microspheres prepared in step 1 are not modified in step 2, and are directly used to prepare a chromatographic column, and the obtained chromatogram is as shown in Figure 6 .

[0117] Comparative Example 3

[0118] The difference from Example 1 is that: a 13X molecular sieve is used to fill the chromatographic column (Molesieve 13X), and the obtained chromatogram is as shown in Figure 7 .

[0119] As can be seen from Examples 1-3 and Comparative Examples 1-3, the modified porous microspheres chromatographic column of the present application can effectively separate ppm-level O2 and Ar in hydrogen, wherein the separation degree of O2 and Ar is greater than 1.5, and baseline separation is achieved. Compared with Example 3, the separation effect of the chromatographic column prepared from the porous microspheres modified by acidification, sulfonation and chlorination in Examples 1 and 2 is better.

[0120] However, the other chromatographic columns cannot effectively separate ppm-level O2 and Ar in hydrogen. The O2 and Ar in hydrogen using 5A molecular sieve chromatographic column and 13X chromatographic column are steamed bun peaks. The O2 and Ar in hydrogen using the styrene-divinylbenzene-acrylonitrile copolymer porous microspheres which are not modified by sulfonation and chlorination are combined peaks, and the separation degree of O2 and Ar is less than 1.5, and baseline separation cannot be achieved.

[0121] The preferred embodiments of the present application are described in detail above, but the present application is not limited thereto. Within the technical concept of the present application, various simple modifications can be made to the technical solutions of the present application, including the combination of various technical features in any other suitable manner, and these simple modifications and combinations should also be considered as disclosed by the present application and fall within the protection scope of the present application.

Claims

1. A modified porous microsphere, characterized by, The modified porous microspheres comprise styrene-divinylbenzene-acrylonitrile copolymers modified by surface benzene ring sulfonation and halogenation; The modified porous microspheres are prepared by the following method: (1) mixing styrene, divinylbenzene and acrylonitrile with an initiator and a porogen to obtain a monomer solution; (2) mixing the monomer solution with a dispersion phase containing a dispersant and performing suspension polymerization to obtain porous microspheres of styrene-divinylbenzene-acrylonitrile copolymers; (3) under acidification conditions, performing sulfonation and halogenation reduction treatment on the porous microspheres of styrene-divinylbenzene-acrylonitrile copolymers to obtain the modified porous microspheres; In step (3), the sulfonation and halogenation reduction treatment comprises: in a mixed solution of sulfuric acid and nitric acid, contacting the porous microspheres of styrene-divinylbenzene-acrylonitrile copolymers with sulfite and halide, and performing sulfonation and halogenation reduction treatment to obtain the product after acidification treatment.

2. The modified porous microsphere of claim 1, wherein, In the styrene-divinylbenzene-acrylonitrile copolymers, the weight ratio of styrene units, divinylbenzene units and acrylonitrile units is (25-45):(20-40):(10-30); and / or The number average molecular weight of the styrene-divinylbenzene-acrylonitrile copolymers is 10000-60000 g / mol.

3. The modified porous microsphere of claim 2, wherein, The divinylbenzene units are p-divinylbenzene units and / or m-divinylbenzene units; and / or The halogenated modified halogen group is chlorine; and / or The mass ratio of surface elements of the modified porous microspheres is C (65-75):O (8-15):S (6-12):Cl (7-13).

4. The modified porous microsphere of any one of claims 1-3, wherein, The pore size of the modified porous microspheres is 20-100 nm; and / or The particle size of the modified porous microspheres is 150-1000 μm; and / or The modified porous microspheres have a BET specific surface area of 30-40 m 2 / g; and / or The column packing density of the modified porous microspheres is 0.2-0.5 g / mL.

5. A method for preparing a modified porous microsphere, characterized by, The method comprises: (1) mixing styrene, divinylbenzene and acrylonitrile with an initiator and a porogen to obtain a monomer solution; (2) mixing the monomer solution with a dispersion phase containing a dispersant and performing suspension polymerization to obtain porous microspheres of styrene-divinylbenzene-acrylonitrile copolymers; (3) under acidification conditions, performing sulfonation and halogenation reduction treatment on the porous microspheres of styrene-divinylbenzene-acrylonitrile copolymers to obtain the modified porous microspheres; In step (3), the sulfonation and halogenation reduction treatment comprises: in a mixed solution of sulfuric acid and nitric acid, contacting the porous microspheres of styrene-divinylbenzene-acrylonitrile copolymers with sulfite and halide, and performing sulfonation and halogenation reduction treatment to obtain the product after acidification treatment.

6. The method of claim 5, wherein, In step (1), the initiator is a peroxide and / or an azo compound; and / or The porogen is selected from one or more of ethyl acetate, paraffin, gasoline, kerosene, n-C12-C18 alkyl alcohol; and / or The divinylbenzene is p-divinylbenzene and / or m-divinylbenzene.

7. The method of claim 6, wherein, In step (1), the initiator is at least one selected from the group consisting of azobisisobutyronitrile, azobisisoheptyl nitrile, benzoyl peroxide and tert-butyl hydroperoxide.

8. The method of claim 6, wherein, The use amount ratio of styrene, divinylbenzene, acrylonitrile, initiator and porogen is (25-45):(20-40):(10-30):(0.5-3):(0.5-3) by weight; and / or The solvent of the monomer solution is at least one selected from the group consisting of toluene, p-xylene and ethylbenzene.

9. The method of claim 5, wherein, In step (2), the dispersant is C12-C22 alkyl tris C1-C6 alkyl ammonium halide; and / or The dispersed phase is an aqueous phase.

10. The method of claim 9, wherein, In step (2), the dispersant is one or more selected from the group consisting of dodecyltrimethylammonium chloride, dodecyltrimethylammonium bromide, dodecyltriethylammonium chloride, dodecyltriethylammonium bromide, tetradecyltrimethylammonium chloride, tetradecyltrimethylammonium bromide, tetradecyltriethylammonium chloride, tetradecyltriethylammonium bromide, hexadecyltrimethylammonium chloride, hexadecyltrimethylammonium bromide, hexadecyltriethylammonium chloride, hexadecyltriethylammonium bromide, octadecyltrimethylammonium chloride, octadecyltrimethylammonium bromide, octadecyltriethylammonium chloride and octadecyltriethylammonium bromide.

11. The method of claim 10, wherein, In step (2), the dispersant is one or more selected from the group consisting of dodecyltrimethylammonium chloride, dodecyltrimethylammonium bromide, dodecyltriethylammonium chloride, dodecyltriethylammonium bromide, hexadecyltrimethylammonium chloride, hexadecyltrimethylammonium bromide, hexadecyltriethylammonium chloride and hexadecyltriethylammonium bromide.

12. The method of claim 9, wherein, The use amount of water is 3-20 parts by weight, and the use amount of dispersant is 0.01-0.05 parts by weight, compared to 1 part by weight of the total weight of styrene, divinylbenzene and acrylonitrile.

13. The method as recited in claim 5, wherein, In step (2), the suspension polymerization conditions include: temperature is 50-95℃, and time is 5-10h.

14. The method of claim 13, wherein, The suspension polymerization mode is to react at 55-65℃ for 0.5-1.5h, then react at 80-90℃ for 1-2h, and then react at 85-95℃ for 3-5h.

15. The method of claim 5, wherein, In step (3), the concentration of sulfate in the mixed solution of sulfuric acid and nitric acid is 15-40wt%; and / or The weight ratio of the mixed solution of sulfuric acid and nitric acid to the porous microspheres is 5-15:1; and / or The sulfonation and halogen reduction treatment conditions include: temperature is 50-70℃, vacuum degree is less than 0.1 MPa, and time is 6-10h.

16. The method of claim 15, wherein, In step (3), the concentration of sulfate in the mixed solution of sulfuric acid and nitric acid is 20-30wt%, and the concentration of nitrate is 40-50wt%.

17. The method of claim 5, wherein, In step (3), the sulfonation and halogen reduction treatment mode includes: performing acidification treatment on the porous microspheres of the styrene-divinylbenzene-acrylonitrile copolymer, then contacting the acidification treated product with sulfite and halide, and performing sulfonation and halogen reduction treatment to obtain the modified porous microspheres.

18. The method of claim 17, wherein, The acidification treatment includes acidifying the porous microspheres in a mixed solution of nitric acid and sulfuric acid to obtain an acidification-treated product. and / or The acidification treatment is performed at a temperature of 50-70°C, a vacuum degree of less than 0.1 MPa, and for a time of 2-6 h. The sulfonation and halogen reduction treatment is performed at a temperature of 50-70°C, a vacuum degree of less than 0.1 MPa, and for a time of 1-3 h.

19. The method of any one of claims 5-18, wherein, In step (3), the amount of the sulfite is 5-40 parts by weight and the amount of the halide is 5-40 parts by weight, based on 100 parts by weight of the porous microspheres. The sulfite is sodium sulfite and / or potassium sulfite. The halide is sodium chloride and / or potassium chloride.

20. The modified porous microspheres prepared by the method of any one of claims 5-19.

21. A separating device, characterized by The separation device is packed with the modified porous microspheres of any one of claims 1-4 and 20.

22. The separation device of claim 21, wherein, The separation device is a chromatographic column.

23. Use of the modified porous microspheres of any one of claims 1-4 and 20 or the separation device of claim 21 or 22 in separating or determining the content of O2 and Ar in a hydrogen raw material.

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